TW201541247A - Method and circuit of detecting attachment and detachment between a portable device and a power converter - Google Patents

Abstract

A method and a circuit of detecting attachment and detachment between a portable device and a power converter are provided. The method and the circuit confirm attachment of the portable device to the power converter and generate an attachment signal. The method and the circuit further detect a bus voltage of the power converter for confirming detachment of the portable device from the power converter.

Description

Method and circuit for detecting connection and extraction between a portable device and a power converter 【0001】

The present invention relates to a power supply, and more particularly to a method and circuit for detecting and disconnecting a portable device from a power converter.

【0002】

In the past few years, portable devices (PDs) have become a necessity for the people. Power converters (chargers) designed for portable devices are usually packaged with the portable device in the same vending box provided by the manufacturer, which guarantees that the portable device is always in accordance with the manufacturer's power supply specifications. The power is supplied below.

[0003]

In recent years, more and more chargers use a universal serial bus (USB) transmission line to connect the corresponding portable devices. These chargers using USB transmission lines gradually replace the use of twisted pair transmission lines. Traditional charger. In addition to the two twisted wires that function as the power supply and ground terminals, the USB cable has two additional data lines to define the type of charging device, such as the standard downlink ( Standard Downstream Port (SDP), Charging Downstream Port (CDP) and Dedicated Charging Port (DCP). The above two data lines have recently been used for communication between the portable device and the charger, for example, the power supply level of the charger is appropriately changed in accordance with the requirements from the portable device.

[0004]

U.S. Patent Application Publication No. 2010/0052620 A1 provides a battery charger wafer with built-in USB detection, as shown in Figures 1A and 1B. It determines via the data pin that the input voltage source contains a USB voltage or does not include a USB voltage. However, it is not possible to confirm that the portable device is removed from the charger, so the industry is looking for a method and circuit for detecting the removal of the portable device from the charger.

[0005]

It is an object of the present invention to provide a circuit and method for detecting a portable device (PD) connection and detaching from a power converter (charger).

[0006]

The invention provides a circuit for detecting connection and removal between a portable device (PD) and a power converter, comprising a portable device connection detecting circuit and a portable device removing detecting circuit. The portable device connection detecting circuit is coupled to at least one connection end of the power converter to confirm that the portable device is connected to the power converter and generates a connection signal. The portable device removing detection circuit detects a bus voltage of the power converter according to the uniform energy signal, and the enabling signal is generated when the power converter enters a light load state, and the portable device removes the detecting circuit by detecting the convergence of the power converter. A voltage drop across the voltage is verified, and the portable device is removed from the power converter. The at least one connection end of the power converter may be a data terminal or a current sensing terminal. The circuit of the present invention further includes a load detection circuit that detects the light load state of the power converter based on the connection signal and generates an enable signal.

【0007】

When the portable device connection detecting circuit detects that the voltage at the data terminal increases, the portable device connection detecting circuit confirms that the portable device is connected to the power converter. It can also be confirmed that the portable device is connected to the power converter by recognizing the same pattern current generated by the portable device. The load detection circuit detects a voltage of one of the power converters to detect the light load state of the power converter and generate an enable signal. The circuit of the present invention further includes a gate driver coupled to a busbar switch between the output capacitor of one of the power converters and a busbar capacitor to generate a busbar voltage across the busbar capacitor.

[0008]

The portable device removal detection circuit controls the gate driver according to the enable signal, and cuts off the bus bar switch. The portable device removal detection circuit records the busbar voltage before the cut-off bus switch, and monitors the voltage drop of the busbar voltage after the busbar switch is turned off to confirm that the portable device is removed from the power converter. When the enable signal indicates the light load state of the power converter, the portable device pull-out detection circuit controls the gate driver cut-off bus switch.

【0009】

The invention also provides a method for detecting connection and removal between a portable device (PD) and a power converter, which comprises confirming that the portable device is connected to the power converter and generating a connection signal; The signal detects a bus voltage of the power converter, and the enable signal is generated when the power converter enters a light load state. The portable device is removed from the power converter by detecting a voltage drop of the busbar voltage of the power converter. A connection signal can be generated by detecting a voltage at a data terminal of one of the power converters. The connection signal can also be generated by identifying the same plate current at the current sense terminal of the power converter, and the template current is generated by the portable device. When it is detected that the voltage at the data terminal increases, it is confirmed that the portable device is connected to the power converter.

[0010]

The method of the present invention also includes detecting a voltage of one of the transformers of the power converter based on the connection signal to detect a light load condition of the power converter and generate an enable signal. The method also includes controlling a busbar switch coupled between the output capacitor of one of the power converters and a busbar capacitor to generate a busbar voltage across the busbar capacitor. The method further includes recording the busbar voltage before the cut-off bus switch and monitoring the voltage drop of the busbar voltage after the cut-off busbar switch to confirm that the portable device is removed from the power converter. When the enable signal indicates the light load state of the power converter, the busbar switch is turned off.

10‧‧‧Transformers
11‧‧‧resistance
12‧‧‧ Capacitance
13‧‧‧ diode
25‧‧‧ switch
30‧‧‧Switching controller
31‧‧‧ gate driver
32‧‧‧ Pulse width modulation circuit
40‧‧‧Optocoupler
41‧‧‧Parallel regulator
43‧‧‧resistance
45‧‧‧resistance
46‧‧‧ Capacitance
50‧‧‧Detection circuit
51‧‧‧Load detection circuit
52‧‧‧ squares
53‧‧‧gate driver
55a‧‧‧Portable device connection detection circuit
55b‧‧‧Portable device connection detection circuit
56‧‧‧
57‧‧‧Portable device removal detection circuit
58‧‧‧ square
61‧‧‧resistance
62‧‧‧resistance
65‧‧‧ bus bar switch
500‧‧‧Detection circuit
511‧‧‧ Comparator
513‧‧‧ and gate
515‧‧‧Inverter
516‧‧‧ counter
551‧‧‧ Comparator
552‧‧‧ and gate
553‧‧‧ comparator
571‧‧‧Switch
572‧‧‧ Capacitance
573‧‧‧Operational Amplifier
574‧‧‧ Comparator
575‧‧‧Delay circuit
576‧‧‧ and gate
577‧‧‧Inverter
578‧‧‧Factor
579‧‧‧Factor
580‧‧‧ or gate
581‧‧‧Inverter
582‧‧‧Delay circuit
583‧‧‧Inverter
585‧‧‧ and gate
586‧‧‧Factor
611‧‧‧ square
BUS‧‧‧ busbar voltage terminal
C _BUS ‧‧‧ Busbar Capacitor
C _O ‧‧‧ output capacitor
CS ₊ ‧‧‧current sensing end
CS _- ‧‧‧ current sensing end
D ₊ ‧‧‧ data side
D _- ‧‧‧ data side
DLY‧‧‧ delayed signal
DN‧‧‧ input
DP‧‧‧ input
D _R ‧‧‧Rectifier
EN‧‧‧Energy end
EN_BUS‧‧‧Enable signal
EN_CT‧‧‧Enable signal
EN_SH‧‧‧Sampling signal
GATE‧‧ ‧ extreme
GND‧‧‧ ground terminal
N _P ‧‧‧ primary winding
N _S ‧‧‧secondary winding
R _S ‧‧‧current sense resistor
RS‧‧‧Reset input
RST‧‧‧Reset signal
S _ATC ‧‧‧Connected signal
S _DTC ‧‧‧Drawout signal
/S _DTC ‧‧‧Reverse extraction signal
S _G ‧‧‧ main switching signal
S _W ‧‧‧Switching signal
SX‧‧‧ trigger signal
SY‧‧‧ comparison output signal
T ₅₁₆ ‧‧‧Counting time
T ₅₇₅ ‧‧‧Delayed time
T ₅₈₂ ‧‧‧Delayed time
TFM‧‧‧ transformer voltage terminal
V _BUS ‧‧‧ busbar voltage
VBUS‧‧‧ busbar power supply end
V _CC ‧‧‧ supply voltage
V _{D +} ‧‧‧ voltage
V _{D -} ‧‧‧ voltage
V _FB ‧‧‧Response signal
V _IN ‧‧‧ input voltage
V _OFFSET ‧‧‧Offset voltage
V _OUT ‧‧‧ output voltage
V _RN ‧‧‧ reference signal
V _RP ‧‧‧ reference signal
V _RT ‧‧‧ reference signal
V _SH ‧‧‧Sampling voltage
V _SV ‧‧‧ voltage
V _TFM ‧‧‧ voltage

[0011]

Figure 1A is a block diagram of a conventional USB detection system;
FIG. 1B is a circuit diagram of a conventional USB detecting circuit; FIG.
Figure 2 is a block diagram showing an embodiment of a detecting circuit of the present invention;
3A is a circuit diagram of an embodiment of a power converter having a detection circuit of the present invention;
FIG. 3B is a circuit diagram of another embodiment of a power converter having a detection circuit of the present invention; FIG.
4 is a circuit diagram of an embodiment of a detection circuit of the present invention;
FIG. 5 is a timing diagram of the invention for confirming that the portable device is removed from the power converter;
FIG. 6 is a timing diagram of the unacknowledged portable device being unplugged from the power converter of the present invention; and FIG. 7 is a view of the present invention for confirming that the portable device is connected to the power converter and confirming that the portable device is removed from the power converter A flowchart of one embodiment of the detection method.

[0012]

In order to give your reviewers a better understanding and understanding of the features and effects of the present invention, please refer to the examples and the accompanying diagrams for explanations as follows:

[0013]

Referring to FIG. 2 and FIG. 3A, FIG. 2 is a block diagram of an embodiment of a detection circuit of the present invention, and FIG. 3A is a circuit diagram of an embodiment of a power converter having a detection circuit of the present invention. As shown in FIG. 2 and FIG. 3A, the detecting circuit 50 is coupled to the secondary side of the power converter, and the power converter acts as a charger to provide power to the portable device (PD) coupled to the power converter. And charging the battery of the portable device. The detecting circuit 50 is for detecting that the portable device is connected to the power converter and detecting that the portable device is removed from the power converter. The detailed circuit of the detecting circuit 50 will be described later.

[0014]

The power converter includes a transformer 10 having a primary side winding N _P and a secondary side winding N _S to convert electrical energy from the primary side winding N _P to the secondary side winding N _S . A first end of the primary winding N _P of the transformer 10 receives an input voltage V _IN of one of the power converters. A switch 25 is coupled between a second end of the primary winding N _P of the transformer 10 and a ground. The switch 25 is used to switch the transformer 10 to convert electrical energy.

[0015]

As shown in FIG. 3A, a resistor 11, a capacitor 12 and a diode 13 are coupled to the primary winding N _P . A rectifier D _R , an output capacitor C _O , a bus bar switch 65 and a bus bar capacitor C _{BUS are} coupled to the secondary side winding N _S . The secondary side winding N _S generates an output voltage V _OUT across the output capacitor C _O via the rectifier D _{R to} generate a bus voltage V _BUS across the bus bar capacitance C _BUS via the bus bar switch 65 . Once the transformer 10 is switched, electrical energy is converted from the primary side winding N _P to the secondary side winding N _S , and the bus bar voltage V _{BUS is} thus generated. In an embodiment of the invention, the output capacitor C _O is a bulk capacitor, such as an electrolytic capacitor, and the capacitance of the output capacitor C _O is much larger than the capacitance of the bus bar capacitor C _BUS . In addition, the bus bar switch 65 coupled between the output capacitor C _O and the bus bar capacitor C _BUS may be a P-type metal oxide semiconductor field effect transistor (MOSFET).

[0016]

A switching controller 30 is used to control the switch 25 to switch the transformer 10. The switching controller 30 includes a gate driver 31 and a Pulse Width Modulation (PWM) circuit 32. The pulse width modulation circuit 32 generates a pulse width modulation signal according to a feedback signal V _FB , and the feedback signal V _{FB is} associated with the load state of the power converter. The gate driver 31 receives the pulse width modulation signal of the pulse width modulation circuit 32 to generate a main switching signal S _G . The main switching signal S _G drives the switch 25 to regulate the output voltage V _OUT and the bus voltage V _BUS .

[0017]

The power converter has four connection ends, which are respectively a bus power supply terminal VBUS, data terminals D ₊ , D _- and a ground terminal GND, and the bus terminal power terminal VBUS and the ground terminal GND are respectively coupled to the secondary side winding N _{S .} Both ends. The bus bar switch 65 and the bus bar capacitor C _{BUS are} coupled to the bus bar power terminal VBUS. The portable device also has four terminals VBUS, D ₊ , D _- and GND to couple the power converter by a transmission line (not shown), such as a universal serial bus (USB). The transmission line has four wires (one bus power cable, two data wires and one ground wire) for connecting the four terminals of the power converter and the four terminals of the portable device. The power converter supplies power to the portable device via the power line and the ground line of the bus line at the bus terminal VBUS and the ground GND respectively. The portable information terminal device via the D _{+ and} D _- transmitting commands / signals to the power converter.

[0018]

The power converter further includes a feedback circuit including an optical coupler 40, a shunt regulator 41 and a voltage dividing circuit including resistors 61 and 62 to generate a feedback signal V _FB . The voltage dividing circuit is coupled between the bus terminal power terminal VBUS and the ground terminal GND to divide the bus bar voltage V _BUS . The optocoupler 40 is coupled between the bus power supply terminal VBUS and the pulse width modulation circuit 32 to generate a feedback signal V _FB . The optocoupler 40 is further coupled to the ground GND via the shunt regulator 41, and the shunt regulator 41 is coupled to the voltage dividing circuit to receive the divided voltage generated by the voltage dividing circuit.

[0019]

In addition, a voltage dividing circuit including resistors 43 and 45 is coupled between the two ends of the secondary winding N _S to divide a voltage across the secondary winding N _S of the transformer 10 . The divided voltages generated by the resistors 43 and 45 charge a capacitor 46 coupled to the resistors 43, 45 to generate a voltage V _TFM across the capacitor 46. The voltage V _TFM represents the transformer voltage of the secondary winding N _S . Therefore, the load state of the power converter can be observed from the switching waveform of the voltage V _TFM . The detecting circuit 50 has five terminals, which are respectively a transformer voltage terminal TFM, a gate terminal GATE, a bus voltage terminal BUS, and two input terminals DN and DP. The detecting circuit 50 further includes a load detecting circuit 51, a gate driver 53, a portable device connection detecting circuit 55a, and a portable device removing detecting circuit 57. The input terminals DP and DN are coupled to the data terminals D ₊ and D _{− , respectively} . One embodiment of the present invention, in the embodiment, the portable device is connected via input detection circuit 55a is coupled to the DP and DN data terminal D _- and D _+, to detect the bits in the data terminal D _- one of the voltage V _{D -} (such as Figure 4 shows the voltage V _{D +} (as shown in Figure 4) at the data terminal D ₊ to confirm that the portable device is connected to the power converter.

[0020]

As shown in block 56 of FIG. 2, the portable device connection detecting circuit 55a detects the portable device by detecting an increase in the voltage V _{D -} and/or the voltage V _{D +} during continuous charging of the portable device ( For example, a mobile phone is connected to a power converter. The portable device connection detecting circuit 55a will generate a connection signal S _ATC according to the detection result. According to another embodiment of the present invention, the portable device connection detecting circuit 55a is coupled only to the input terminal DN or DP, and receives the voltage V _{D -} or the voltage V _{D +} to detect the connection of the portable device.

[0021]

The load detection circuit 51 is coupled to the transformer voltage terminal TFM and detects the voltage V _TFM to detect the load state of the power converter and generate the coincidence signal EN_BUS. Once the battery of the portable device is fully charged, the load at the power supply terminal VBUS of the busbar will be converted to a light load state. That is, the load detecting circuit 51 confirms whether the battery of the portable device is fully charged. As shown in block 52 of FIG. 2, the load detecting circuit 51 detects the state of fullness of the battery by detecting the transformer voltage of the transformer 10. Even if the battery is not fully charged, the load detection circuit 51 can detect other small output load states via various modes of operation of the portable device. The load detecting circuit 51 is further coupled to the portable device connection detecting circuit 55a and the portable device removing detecting circuit 57 to receive the connecting signal S _ATC and the portable device removing detecting circuit 57 to generate a pull-out signal S _DTC .

[0022]

Please refer to FIG. 3B, which is another embodiment of the present invention. A detection circuit 500 has five terminals, which are a transformer voltage terminal TFM, a gate terminal GATE, a bus voltage terminal BUS, and current sensing terminals CS ₊ and CS _- . A portable device connection detecting circuit 55b is coupled to the current sensing terminals CS ₊ and CS _- . The current sensing terminals CS ₊ and CS _{- are} connected to both ends of a current sensing resistor R _S , and the current sensing resistor R _{S is} connected between the bus bar capacitor C _BUS and the bus bar power terminal VBUS. The current sensing terminals CS ₊ and CS _- sense the same pattern current I _BUS extracted by the portable device through the bus terminal power terminal VBUS. In one embodiment of the invention, the template current I _BUS may be a serial current waveform from the portable device having a short pulse width. In another embodiment, the template current I _BUS can be any waveform that the portable device connection detection circuit 55b can recognize. Once the portable device connection detecting circuit 55b successfully recognizes the template current I _BUS , it is confirmed that the portable device is connected to the power converter and generates a connection signal S _ATC .

[0023]

The portable device removal detecting circuit 57 is coupled to the bus bar voltage terminal BUS, and the portable device removing detecting circuit 57 detects the bus bar voltage V _BUS according to the enabling signal EN_BUS and after the bus bar switch 65 is turned off. Once the portable device is removed from the power converter, there will be no load at the bus terminal VBUS. The load state of the power converter will be changed to the no-load state, and the Equivalent Series Resistance (ESR) or leakage current of the bus bar capacitor C _BUS will cause a small but not significant voltage drop of the bus bar voltage V _BUS . In addition, once the portable device consumes a very small power source, such as the portable device is fully charged and not removed from the power converter, the load state of the power converter will be in a light load state. Compared with the no-load state of the portable device being removed from the power converter, when the portable device is still connected to the power converter, the bus voltage V _BUS will have a significant voltage drop, which is caused by the portable device. The load state, even if it is a light load state, will consume energy on the busbar capacitor C _BUS across a small capacitance value for a short time.

[0024]

As can be seen from the above, when the portable device removal detecting circuit 57 receives the enable signal EN_BUS from the load detecting circuit 51, it indicates a light load state (the portable device has been fully charged), and the portable device is removed. The detection circuit 57 detects the bus voltage V _BUS to confirm that the portable device is removed from the power converter. The portable device removal detecting circuit 57 further generates a plucking signal S _DTC and a switching signal S _W , and the plucking signal S _DTC indicates whether the portable device is detached from the power converter. Whenever the bus bar voltage V _{BUS is} to be detected, the switching signal S _W is turned off by the bus bar switch 65. As shown in block 58 of FIG. 2, the portable device removal detecting circuit 57 records the bus bar voltage V _BUS before the bus bar switch 65 (the P-type MOSFET shown in FIG. 2) is turned off, and then after the bus bar switch 65 is turned off. The voltage drop of the bus bar voltage V _BUS is monitored to confirm that the portable device is removed from the power converter.

[0025]

Please refer to FIG. 4, which is a circuit diagram of an embodiment of the detection circuit 50 of the present invention. As shown in FIG. 4, the portable device connection detecting circuit 55a includes comparators 551, 553 and a gate 552. The negative input terminal of the comparator 551 is coupled to the input terminal DN to receive the voltage V _{D -} , and a reference signal V _{RN is} supplied to the positive input terminal of the comparator 551. The negative input terminal of the comparator 553 is coupled to the input terminal DP to receive the voltage V _{D +} , and a reference signal V _{RP is} supplied to the positive input terminal of the comparator 553. The outputs of the comparators 551 and 553 are coupled to the input of the gate 552, and the output of the gate 552 is coupled to generate a connection signal S _ATC .

[0026]

In order to comply with battery charging specifications, such as BC1.2, when the portable device is connected to the charger, the voltage V _{D -} and / or voltage V _{D +} will be higher than a reference voltage at least once. Therefore, as shown in FIG. 5, when the level of the voltage V _{D -} is higher than the level of the reference signal V _RN and/or the level of the voltage V _{D +} is higher than the level of the reference signal V _RP , the comparator 551 or The level of the comparison output signal at the output of the comparator 553 is converted to a logic low level, so that the level of the connection signal S _ATC is also converted to a logic low level. Therefore, when the portable device connection detecting circuit 55a detects that the voltage V _{D +} or V _{D - is} increased, it is confirmed that the portable device is connected to the power converter. In another embodiment of the present invention, the portable device connection detecting circuit 55a includes only one of the comparator 551 or the comparator 553 to detect that the portable device is connected to the power converter.

[0027]

The load detection circuit 51 includes a comparator 511, a gate 513, an inverter 515, and a counter 516. The negative input of the comparator 511 is coupled to the transformer voltage terminal TFM to receive the voltage V _TFM , and the voltage V _TFM represents the transformer voltage of the transformer 10 (shown in FIG. 3A). A reference signal V _RT is supplied to the positive input terminal, an output terminal of the comparator 511. Comparator 511 generates an enable signal to the counter EN_CT enable terminal EN 516 of the actuator. As shown in FIG. 5, when the level of the voltage V _TFM is lower than the level of the reference signal V _RT , the level of the enable signal EN_CT is converted to a logic high level (enabled), so that the counter 516 starts counting. A count time T ₅₁₆ shown in FIG.

[0028]

The gate 513 is coupled to the output of the gate 552 and the output of the comparator 511 to receive the connection signal S _ATC and the enable signal EN_CT. The gate 513 further receives an inverted pull-out signal /S _DTC outputted from the output of the inverter 515. The inverter 515 inverts the detachable signal S _DTC outputted by the portable device detaching detection circuit 57 to generate an inverted plucking signal /S _DTC . The output end of the gate 513 is coupled to the reset input terminal RS of the counter 516, and generates a reset signal RST according to the connection signal S _ATC , the enable signal EN_CT and the inverted pull signal /S _DTC , and resets the counter 516 , the counter 516 generates an enable signal EN_BUS at its output terminal Q.

[0029]

Please refer to FIG. 5, which is a timing diagram for confirming that the portable device is removed from the power converter. As shown, during the counting time T ₅₁₆ , the level of the voltage V _TFM continues to be lower than the level of the reference signal V _RT , and when the counter 516 also counts the counting time T ₅₁₆ , the enable signal EN_BUS will be converted to a logic high. Level (enable). Therefore, the portable device removal detecting circuit 57 detects the bus bar voltage V _BUS according to the enable signal EN_BUS to confirm that the portable device is removed from the power converter and generates the plucking signal S _DTC .

[0030]

The portable device removal detection circuit 57 includes a delay circuit 582, an inverter 583, a gate 585, a switch 571, a capacitor 572, an operational amplifier 573, and a comparator 574. The delay circuit 582 is coupled to the counter 516 to receive the enable signal EN_BUS, and delays the enable signal EN_BUS by a delay time T ₅₈₂ (shown in FIG. 5) to generate a delay signal DLY. The first input terminal of the gate 585 is coupled to the counter 516 to receive the enable signal EN_BUS, and the second input terminal of the gate 585 receives the delay signal DLY via the inverter 583, and the gate 585 generates a sampling signal EN_SH at the output. As shown in FIG. 5, the pulse width (on time) of the sampling signal EN_SH is equal to the delay time T ₅₈₂ .

[0031]

The switch 571 controlled by the sampling signal EN_SH is coupled between the capacitor 572 and the bus voltage terminal BUS of the detecting circuit 50 to sample the bus bar voltage V _BUS . The bus terminal voltage terminal BUS of the detecting circuit 50 is further connected to the bus bar power terminal VBUS. Therefore, when the switch 571 is turned on, a sampling voltage V _SH across the capacitor 572 is generated and equal to the bus bar voltage V _BUS . The positive input terminal of the operational amplifier 573 receives the sampling voltage V _SH , and the negative input terminal and the output terminal of the operational amplifier 573 are coupled to each other as a buffer.

[0032]

An offset voltage _{VOFFSET is} coupled to the output of the operational amplifier 573 to generate a voltage V _SV . As shown in FIG. 5, the voltage level of the voltage V _{SV is} a level difference between the sampling voltage V _SH (equal to the bus bar voltage V _BUS ) and the offset voltage V _OFFSET . The negative input terminal of the comparator 574 receives the voltage V _SV , the positive input terminal of the comparator 574 is coupled to the bus terminal voltage terminal BUS, and the bus bar voltage terminal BUS is coupled to the bus bar power terminal VBUS to receive the bus bar voltage V _BUS . Comparator 574 compares voltage V _SV with bus voltage V _BUS to produce a comparison output signal SY. As shown in FIG. 5, when the level of the bus bar voltage V _BUS is higher than the level of the voltage V _SV , the level of the comparison output signal SY is a logic high level. Conversely, as shown in FIG. 6, when the level of the bus bar voltage V _BUS is lower than the level of the voltage V _SV , the level of the comparison output signal SY is converted to a logic low level.

[0033]

When the portable device is fully charged and removed from the power converter, the bus terminal VBUS will be unloaded and the voltage drop of the bus bar voltage V _BUS will only change slightly. As shown in FIG. 5, after the level of the sampling signal EN_SH transitions to a logic high level (enable) and the voltage V _{SV is} generated, the level of the bus bar voltage V _BUS continues to be higher than the level of the voltage V _SV , and The level of the comparison output signal SY is a logic high level. In this way, it is confirmed that the portable device is removed from the power converter. Conversely, as shown in FIG. 6, after the level of the sampling signal EN_SH transitions to a logic high level (enable) and the voltage V _SV has been generated, the level of the bus bar voltage V _BUS is lower than the level of the voltage V _SV . Then, the level of the comparison output signal SY is changed to a logic low level. As such, the portable device is not confirmed to be removed from the power converter.

[0034]

Referring to FIG. 4, the portable device removal detecting circuit 57 further includes a delay circuit 575, inverters 577, 581, a gate 576, a gate 580, and flip-flops 578, 579 and 586. The delay circuit 575 is coupled to the delay circuit 582 to receive the delay signal DLY and delay the delay signal DLY by a delay time T ₅₇₅ (as shown in FIG. 5). The first input of the AND gate 576 receives the output signal of the delay circuit 575 via the inverter 577, and the second input of the gate 576 receives the delayed signal DLY. The gate 576 generates a trigger signal SX. As shown in FIG. 5, the pulse width (on time) of the trigger signal SX is determined by the delay time T ₅₇₅ .

[0035]

The flip-flop 578 is triggered by the comparison output signal SY, and is reset by the delay signal DLY, and a supply voltage V _{CC is} supplied to the data terminal D of the flip-flop 578. The first input terminal of the OR gate 580 is coupled to the output terminal Q of the flip-flop 578 to receive the output signal of the flip-flop 578. The second input of the OR gate 580 receives the delay signal DLY via the inverter 581, or the gate 580 produces a switching signal S _W at the output. The gate driver 53 is coupled to the gate 580 to receive the switching signal S _W and to control the bus bar switch 65 shown in FIG. 3A.

[0036]

The switching signal S _W is used to reset the flip-flop 579. The trigger signal SX triggers the flip-flop 579. The data terminal D of the flip-flop 579 is coupled to the comparator 574 to receive the comparison output signal SY, and the output of the flip-flop 579. The terminal Q is coupled to the flip flop 586 to trigger the flip flop 586. The supply voltage V _{CC is} supplied to the data terminal D of the flip-flop 586, and the flip-flop 586 generates a pluck signal S _DTC at the output terminal Q to indicate whether the portable device is detached from the power converter. The flip flop 586 is reset by the connection signal S _ATC .

[0037]

Please refer to FIG. 4 and FIG. 5 together. FIG. 5 is a timing diagram of the invention for confirming that the portable device is removed from the power converter. As shown in FIG. 5, when the portable device connection detecting circuit 55a detects that the level of the voltage V _{D -} or V _{D +} is higher than the level of the reference signal V _RN or V _RP , the portable device connection detecting circuit 55a Confirm that the portable device is connected to the power converter (charger). Therefore, the level of the connection signal S _ATC will be converted to a logic low level.

[0038]

After the portable device is connected to the power converter, the voltages V _{D -} and V _{D +} are lower than the reference signals V _RN and V _RP , respectively, so the level of the connection signal S _ATC will be converted into logic again. High standard.

[0039]

Under the definition of some manufacturers of portable devices, especially for adaptive charging functions, the voltage V _{D -} and / or V _{D +} will be lowered, indicating that the portable device has been removed. However, under the definition of the manufacturer of other portable devices, the voltage V _{D -} and / or V _{D +} will automatically drop after a certain time, this specific time follows the voltage V _{D -} and / Or after the rising edge of V _{D +} . Regardless of the defined situation, the present invention provides a load detection circuit 51 that detects the load state of the power converter for subsequent confirmation steps (portable device connection or detachment from the power converter).

[0040]

Referring to FIG. 5, at time point A, the power converter enters an intermittent burst switching operation. The next rising waveform of the voltage V _TFM will be delayed because the non-switching time (cut-off time) of the main switching signal S _G (as shown in FIG. 3A) is prolonged in the light load state for the purpose of saving power. . The intermittent power-saving switching operation mentioned above may occur in the removal of the portable device or the light load state caused by the portable device, such as a fully charged battery level. During the non-switching time period, the level of the voltage V _TFM of the transformer 10 (shown in FIG. 3A ) will remain lower than the reference signal V _RT , which will result in a logic high level (enable). The signal EN_CT can be signaled to initiate the counting of counter 516. Once the enable signal EN_CT remains at the logic high level for a count time T ₅₁₆ , the level of the enable signal EN_BUS generated by the load detection circuit 51 will be converted to a logic high level (enable) to enable the portable device The detection circuit 57 is removed and the inspection of the portable device is removed from the power converter.

[0041]

In response to the above, the level of the sampling signal EN_SH generated by the gate 585 is converted to a logic high level (enabled), and the switch 571 is used to sample and hold (record) the bus bar voltage V _BUS to the capacitor 572. The level of the voltage V _SV will be equal to the voltage difference between the sampling voltage V _SH (bus bar voltage V _BUS ) and the offset voltage V _OFFSET . After a time period T ₅₈₂ after the rising edge of the enable signal EN_BUS, the delay signal DLY will transition to a logic high level. The level of the switching signal S _W will transition to a logic low level (disabled) to turn off the bus switch 65 (shown in Figure 3A). When the portable device has been removed, there will be no load at the busbar power supply terminal VBUS, and after the busbar switch 65 is turned off, the voltage drop of the busbar voltage V _BUS will only slightly change. The level of the bus voltage V _BUS will remain above the level of the voltage V _SV . The logic high level delay signal DLY will maintain the trigger signal SX at a logic high level until the time period T ₅₇₅ has elapsed. Once the level of the trigger signal SX transitions to a logic low level, the level of the pull-down signal S _DTC will transition to a logic high level, which indicates that the portable device pull-out detection circuit 57 confirms that the portable device is removed from the power converter. . In addition, when the level of the delay signal DLY transitions to a logic low level, the level of the switching signal S _W will again transition to a logic high level (enable) to turn on the bus switch 65.

[0042]

Please refer to FIG. 4 and FIG. 6 together. FIG. 6 is a timing diagram of the unacknowledged portable device being removed from the power converter according to the present invention. As shown in FIG. 6, when the sampling signal EN_SH transitions to a logic high level, the bus voltage V _BUS will be sampled and saved across the capacitor 572. Therefore, the level of the voltage V _SV will be equal to the voltage difference between the sampling voltage V _SH (equal to the bus bar voltage V _BUS ) and the offset voltage V _OFFSET . Whenever the delay signal DLY transitions to a logic high level after the delay time T ₅₈₂ , the switching signal S _W will be disabled to turn off the bus bar switch 65, wherein the delay time T ₅₈₂ follows the rising edge of the sampling signal EN_SH. The busbar capacitor C _BUS has a smaller capacitance than the output capacitor C _O . When the quasi-position of the bus voltage V _BUS is significantly lower in the time period T ₅₇₅ and the transition is lower than the level of the voltage V _SV , this means that the load is still connected to the bus terminal VBUS. At this time, the comparison output signal SY is at a logic low level, which again enables the switching signal S _W via the flip-flop 578 and the OR gate 580 to turn on the bus bar switch 65. When the level of the trigger signal SX changes to a logic low level, the level of the plucking signal S _DTC remains at a logic low level, so that the portable device is not confirmed to be removed from the power converter, indicating that the portable device is still Connected to a power converter.

[0043]

Please refer to FIG. 7 , which is a flowchart of an embodiment of a method for detecting that a portable device is connected to a power converter and that the portable device is removed from the power converter. As shown, the detection method begins by turning on the AC power source (step 601) to activate the power converter (charger) such that the output voltage V _OUT (shown in FIG. 3A) will climb and the bus bar switch 65 (As shown in FIG. 3A), the off state is maintained until the output voltage V _OUT is established (steps 602 and 603). Once the output voltage V _{OUT is} established, the bus switch 65 will be turned on, at which point the bus voltage V _BUS will be equal to the output voltage V _OUT (step 604).

[0044]

Next, the portable device connection detecting circuit 55a (shown in FIG. 3A) detects whether the level of the voltage V _{D +} is higher than or equal to the level of the reference signal V _RP and/or whether the level of the voltage V _{D −} is high. At or equal to the level of the reference signal V _RN (step 605). Once the level of the voltage V _{D +} is higher than or equal to the level of the reference signal V _RP , and/or the level of the voltage V _{D −} is higher than or equal to the level of the reference signal V _RN , the portable device connection is confirmed. The power converter (shown as block 611). If the portable device is not confirmed to be connected to the power converter, the portable device connection detecting circuit 55a will again detect whether the portable device is connected to the power converter (step 605).

[0045]

Next, the load detecting circuit 51 checks whether the non-switching time of the transformer 10 is longer than or equal to the counting time T ₅₁₆ (step 606). At this step, the load detecting circuit 51 checks whether the load state of the power converter is a light load state. The load detecting circuit 51 detects the level of the voltage V _TFM (the voltage of the transformer 10) in accordance with the connection signal S _ATC , and detects the load state of the power converter. In the light load state, for example, the intermittent switching operation of the main switching signal S _G (shown in FIG. 3A), the level of the voltage V _TFM will continue to be lower than the level of the reference signal V _RT . Specific cycle time. The main switching signal S _G includes a non-switching time (cutoff time). When the non-switching time of the main switching signal S _G is shorter than the counting time T ₅₁₆ , the load detecting circuit 51 will recheck the load state of the power converter (step 606). When the non-switching time of the transformer 10 is longer than or equal to the counting time T ₅₁₆ , this means that the load state of the power converter is changed to the light load state, so that the portable device has been charged. The portable device removal detection circuit 57 will sample and hold the bus voltage V _BUS (step 607).

[0046]

Next, the portable device removal detecting circuit 57 _turns off the bus bar switch 65 after the delay time T ₅₈₂ (step 608). As shown in FIG. 5, the delay time T ₅₈₂ is the pulse width of the sampling signal EN_SH. Next, during the delay time T ₅₇₅ shown in FIG. 5, the portable device removal detecting circuit 57 checks whether the level of the bus bar voltage V _BUS is higher than or equal to the sampling voltage V _SH and the offset voltage V _OFFSET . The level difference (step 609). If the level of the bus bar voltage V _BUS is higher than or equal to the aforementioned level difference, it is confirmed that the portable device has been removed from the power converter (step 610). Conversely, the portable device removal detection circuit 57 will again turn on the bus bar switch 65 (step 612). At this point, the detection process will return to step 606 to reconfirm whether the portable device is removed from the power converter.

[0047]

However, the above description is only an embodiment of the present invention, and is not intended to limit the scope of the present invention, and the equivalent changes and modifications of the structure, features, and spirits described in the claims of the present invention should be It is included in the scope of the patent application of the present invention.

10‧‧‧Transformers

11‧‧‧resistance

12‧‧‧ Capacitance

13‧‧‧ diode

25‧‧‧ switch

30‧‧‧Switching controller

31‧‧‧ gate driver

32‧‧‧ Pulse width modulation circuit

40‧‧‧Optocoupler

41‧‧‧Parallel regulator

43‧‧‧resistance

45‧‧‧resistance

46‧‧‧ Capacitance

50‧‧‧Detection circuit

51‧‧‧Load detection circuit

53‧‧‧gate driver

55a‧‧‧Portable device connection detection circuit

57‧‧‧Portable device removal detection circuit

61‧‧‧resistance

62‧‧‧resistance

65‧‧‧ bus bar switch

BUS‧‧‧ busbar voltage terminal

C _BUS ‧‧‧ Busbar Capacitor

C _O ‧‧‧ output capacitor

D ₊ ‧‧‧ data side

D _- ‧‧‧ data side

DN‧‧‧ input

DP‧‧‧ input

D _R ‧‧‧Rectifier

EN_BUS‧‧‧Enable signal

GATE‧‧ ‧ extreme

GND‧‧‧ ground terminal

N _P ‧‧‧ primary winding

N _S ‧‧‧secondary winding

S _ATC ‧‧‧Connected signal

S _DTC ‧‧‧Drawout signal

S _G ‧‧‧ main switching signal

S _W ‧‧‧Switching signal

TFM‧‧‧ transformer voltage terminal

V _BUS ‧‧‧ busbar voltage

VBUS‧‧‧ busbar power supply end

V _FB ‧‧‧Response signal

V _IN ‧‧‧ input voltage

V _OUT ‧‧‧ output voltage

V _TFM ‧‧‧ voltage

Claims (18)

[Item 1] A circuit for detecting connection and removal between a portable device and a power converter, comprising:
a portable device is connected to the detection circuit, coupled to at least one connection end of the power converter to confirm that the portable device is connected to the power converter, and generates a connection signal; and a portable device removal detection circuit Detecting a bus voltage of the power converter according to the consistent energy signal, the enabling signal is generated when the power converter enters a light load state, and the portable device removing detection circuit detects the bus voltage of the power converter A voltage drop is made to confirm that the portable device is removed from the power converter. [Item 2] The detecting circuit of claim 1, wherein the at least one connecting end of the power converter is a data end. [Item 3] The detecting circuit of claim 1, wherein the at least one connecting end of the power converter is a current sensing end. [Item 4] The detection circuit of claim 1, further comprising a load detection circuit that detects the light load state of the power converter according to the connection signal and generates the enable signal. [Item 5] The detection circuit of claim 2, wherein the portable device connection detection circuit detects that the voltage of one of the data terminals increases, the portable device connection detection circuit confirms that the portable device is connected to The power converter. [Item 6] The detection circuit of claim 3, wherein the portable device connection detection circuit identifies the same plate current generated by the portable device, and confirms that the portable device is connected to the power converter. [Item 7] The detection circuit of claim 4, wherein the load detection circuit detects a voltage of a transformer of the power converter to detect the light load state of the power converter and generate the enable signal. [Item 8] For example, the detection circuit described in claim 1 further includes:
A gate driver controls a busbar switch coupled between an output capacitor of the power converter and a busbar capacitor to generate the busbar voltage across the busbar capacitor. [Item 9] The detection circuit of claim 8, wherein the portable device removal detection circuit controls the gate driver according to the enable signal to cut off the bus switch, and the portable device removes the detection circuit. The busbar voltage is recorded before the busbar switch is turned off, and the voltage drop of the busbar voltage is monitored after the busbar switch is turned off to confirm that the portable device is removed from the power converter. [Item 10] The detection circuit of claim 9, wherein the portable device removal detection circuit controls the gate driver to turn off the busbar switch when the enable signal indicates the light load state of the power converter. [Item 11] A method for detecting connection and removal between a portable device and a power converter, comprising:
Confirming that the portable device is connected to the power converter and generating a connection signal; and detecting a bus voltage of the power converter according to the consistent energy signal, the enable signal is generated when the power converter enters a light load state And detecting a voltage drop of the bus voltage of the power converter to confirm that the portable device is removed from the power converter. [Item 12] The detection method of claim 11, further comprising detecting a voltage at a data terminal of one of the power converters to generate the connection signal. [Item 13] The detection method of claim 11, further comprising identifying a same plate current at a current sensing end of the power converter to generate the connection signal, the template current being generated by the portable device. [Item 14] The detection method of claim 12, wherein when the voltage at the data terminal is detected to increase, it is confirmed that the portable device is connected to the power converter. [Item 15] For example, the detection method described in claim 11 further includes:
A voltage of a transformer of the power converter is detected according to the connection signal to detect the light load state of the power converter, and the enable signal is generated. [Item 16] For example, the detection method described in claim 11 further includes:
A busbar switch is coupled between the output capacitor of one of the power converters and a busbar capacitor to generate the busbar voltage across the busbar capacitor. [Item 17] For example, the detection method described in claim 16 of the patent application further includes:
The busbar voltage is recorded before the busbar switch is turned off; and after the busbar switch is turned off, the voltage drop of the busbar voltage is monitored to confirm that the portable device is removed from the power converter. [Item 18] The detection method of claim 17, wherein the bus switch is turned off when the enable signal indicates the light load state of the power converter.